/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */
package com.opensource.dbhelp.dbutils.handlers;

import java.sql.ResultSet;
import java.sql.SQLException;

import com.opensource.dbhelp.dbutils.BasicStringRowProcessor;
import com.opensource.dbhelp.dbutils.ResultSetHandler;
import com.opensource.dbhelp.dbutils.StringRowProcessor;

/**
 * <code>ResultSetHandler</code> implementation that converts a <code>ResultSet</code> into an <code>String[]</code>. This class is thread safe.
 * 
 * @see com.opensource.dbhelp.dbutils.ResultSetHandler
 */
public class StringArrayHandler implements ResultSetHandler<String[]> {

	/**
	 * Singleton processor instance that handlers share to save memory. Notice the default scoping to allow only classes in this package to use this instance.
	 */
	static final StringRowProcessor ROW_PROCESSOR = new BasicStringRowProcessor();

	/**
	 * The StringRowProcessor implementation to use when converting rows into arrays.
	 */
	private final StringRowProcessor convert;

	/**
	 * Creates a new instance of ArrayHandler using a <code>BasicRowProcessor</code> for conversion.
	 */
	public StringArrayHandler() {
		this(ROW_PROCESSOR);
	}

	/**
	 * Creates a new instance of ArrayHandler.
	 * 
	 * @param convert
	 *            The <code>StringRowProcessor</code> implementation to use when converting rows into arrays.
	 */
	public StringArrayHandler(StringRowProcessor convert) {
		super();
		this.convert = convert;
	}

	/**
	 * Places the column values from the first row in an <code>Object[]</code>.
	 * 
	 * @return An Object[] or <code>null</code> if there are no rows in the <code>ResultSet</code>.
	 * @throws java.sql.SQLException
	 *             if a database access error occurs
	 * @see com.opensource.dbhelp.dbutils.ResultSetHandler#handle(java.sql.ResultSet)
	 */
	@Override
	public String[] handle(ResultSet rs) throws SQLException {
		return rs.next() ? this.convert.toArray(rs) : null;
	}

}
